DE2152567C3 - Low shrinkage curable polyester resin compositions for moldings with improved adhesion of coatings - Google Patents

Description

The adhesion of coatings to hardened moldings based on polyester is achieved by adding Shrinkage reducing additives to the uncured resin seriously deteriorated the present Invention provides compositions with low shrinkage based on polyester resin for the production of moldings with improved adhesion of coating materials through the addition of certain nitrogen-containing vinyl mc aomers are available for the uncured resin.

Polyester-based resins make up a large proportion of the thermosetting resins business. In general, they comprise the copolymerizable (curable) resin compositions in a larger amount an unsaturated polyester and a smaller amount of a crosslinking monomer (hence the Expression »polyester base«). They can contain a variety of additives and with reinforcing agents Fibers and / or threads as molding compounds (BMC), resin mats, prepregs (SMC) and closed by hand laying molding compounds, all of which come under the general terms "fiber-reinforced polyester" (GF-UP) or GFK are known.

Many products are made from polyester-based resins, e.g. B. Motor vehicle parts, household appliance housings, Hand tools, rocket fuselage cones, etc. To that extent an ornament or surface treatment is required, there were few, if any, difficulties. Hardened Polyester-based resins are mostly chemically inert and receptive to most conventional ones Paints and varnishes. However, the development of these resins in another area has difficult chains in terms of their paintability.

A serious problem with GRP processing is the shrinkage of the plastic during the fofiflpressing and hardening. The density of the crosslinked polymer is considerably higher than the sum of the Seal the separate starting fluids so that the molded plastic during polymerization experiences a pronounced decrease in its volume. This shrinkage is enough to get a accurate compression molding of many parts, especially

25 if the part is large and a smooth surface must have to prevent. The shrinking gives way by dents or voids on the surface of the part, usually in areas of sudden sharpness Change in thickness occurs, as with sprues and ribs.

In an effort to suppress this waning, one has the mixing approach with conventional polyester-based resins in a certain way modified In general, these modifications include the addition of one or more anti-shrinkage elements Additives (»low-shrink«, »low-profile«). There are these are usually fine particles of thermoplastic polymers (see Australian patent specification 24 802 / 67). Although these additives have greatly reduced shrinkage, they pose serious problems when completing the hardened part: namely, they seriously worsen the Adhesion of covering materials to the surface of the hardened polyester moldings.

According to the theory, this deterioration is due in part to the shrinkage additives which migrate to the surface during polymerization. Because of thermoplastic resins it is known that they are less polar than thermosetting ones Resins, this migration causes the surface to be less polar and thus less receptive to the Connection with paints and other cover materials.

The present invention is based on the surprising finding that an addition of small Amounts of certain nitrogen-containing vinyl monomers to the uncured, little shrinking resin Polyester base the degree of adhesion between the resin and the overlying coating material layers increased The increase in the adhesion of coating materials brought about according to the invention is achieved at least the degree of adhesion of the same coating material to hardened surfaces from conventional polyester-based resins and in many cases an even higher degree.

DE-AS 10 49 574 describes thermosetting compositions made of unsaturated polyesters, styrene and nitrogenous Monomers, such as acrylamide or methacrylamide, described. However, these known masses contain no thermoplastic polymers which reduce the hardening shrinkage. The by the addition of such Problems caused by polymers are therefore not addressed in the DE-AS. The hardened ones Resins are said to have better adhesion to glass fabric or glass fibers, while the coating adhesion is not mentioned.

GB-PS 10 12 484 deals with stoving enamels based on unsaturated polyesters, vinyl monomers and amides of monoethylenically unsaturated carboxylic acids, in which the amide hydrogen atom through certain hydroxylalkyl radicals or their derivatives is replaced. According to claim 3, a reaction is the Amido groups provided with formaldehyde and an alkanol. Additives reducing the hardening shrinkage are also not mentioned in this patent specification. The better adhesion mentioned on page 1, lines 75/76 refers to the connection of the cured copolymers with metal surfaces.

From GB-PS 6 55 615 are polymerizable Known masses of unsaturated alkyd resins and certain unsaturated acrylamides (but not styrene) contain. The acrylamides are used in the examples in the high proportion of 50 parts per 100 parts of polyester

The hardening shrinkage reducing additives are used in this patent, which deals with the Improvement of the resin compositions as such and not concerned with adhesion problems, not mentioned.

The object of the present invention is therefore a resin composition based on polyester which can be hardened with low shrinkage with improved adhesion of cover materials to the hardened surfaces of the materials made from them Molded body. The other properties of the hardened GRP molded body should not be adversely affected will. The shaping and hardening should be easy to carry out and accessible to automatic or semi-automatic process control.

The invention is represented by the patent address.

Due to the above prior art, it was ■ not foreseeable that only one addition would be very special nitrogen-containing vinyl monomers the adhesiveness the low-shrinkage curable polyester resin compositions would greatly improve compared to coatings. As the The comparative tests below show other monomers (even some nitrogen-containing vinyl monomers) no increased upper pull liability.

The present invention is based on polyester-based resins which are curable with low shrinkage ("LP-Harze" in the sense how this term is used in plastics engineering} applicable. Resins Polyester-based mixtures are generally mixtures of unsaturated polyester resins with crosslinkable resins Monomers. Polyesters are generally made by esterifying (condensing) polycarboxylic acids and glycols and by removing water to form a viscous liquid "- that of a fusible one Solid, with disproportionately few remaining Carboxyl groups, i.e. a relatively low acid number produced For examples of Polycarboxylic acids that are useful in making polyester resins include dicarboxylic acids,

40

45

v>

Oxalic acid, malonic acid, Succinic acid, glutaric acid, Adipic acid, pimelic acid, Suberic acid, azelaic acid, Sebacic acid, fumaric acid, Maleic acid, phthalic acid (anhydride), Isophthalic acid, terephthalic acid, Hexahydroterephthalic acid, Tetrachlorophthalic acid (anhydride), Chlorophthalic acid (anhydride). Diphenic acid and

Nitrophthalic acid,
and tricarboxylic acids, such as

Tricarballylic acid and Citric acid.

Examples of glycols that are useful in the preparation of v, polyester resins include,

Ethylene glycol, propylene glycol, Ethylene glycol carbonate, butane-23-diol, Trimethylene glycol, butane-1,3-diol,

2-methylpropane-U-diol, µ

2,2-dimethylprepan-13-diol,

2,2-diethy! Propane-U-diol,

cis-but-2-en-1,4-diol,

trans-but-2-en-1,4-diol,

Tetramethylene glycol, pentamethylene glycol, µ Hexamethylene glycol, heptamethylene glycol. Octamethylene glycol, nonamethylene glycol, Decamethylene glycol, undecamethylene glycol, Dodecamethylene glycol, Tridecamethylene glycol, Tetradecamethylene glycol ',, Octadecamethylene glycol, Eicosamethylene glycol, diethylene glycol,

Triethylene glycol, tetraethylene glycol, etc.
In the resulting polyesters, a crosslinkable monomeric compound is blended that can copolymerize with the unsaturation sites (double bonds) introduced into the polyester by the unsaturated carboxylic acids during the esterification reaction. The crosslinking monomer is generally a monomeric liquid of at least one

CH ₂ = C C group

and is commonly referred to as vinyl monomer. These monomers can be of the aliphatic type, aromatic type, heterocyclic type, or a mixture thereof. Typical monomers include
. Styrene, chlorostyrene,

Dichlorostyrene, alkylstyrene,

«-Methyl styrene, vinyl naphthalene,

Diallyl phthalate diallyl maleate, Diallyl fumarate di ^ llyl succinate, Ethyl vinyl ether, diallyl ether, Methyl allyl ethyl ether, methyl vinyl ketone, Divinyl ketone, methyl allyl ketone, Methyl acrylate ethyl acrylate Methyl methacrylate acrylonitrile,

Methacrylonitrile and the like.
These crosslinking monomers are mixed with the polyester to form a highly viscous, crosslinkable ie curable resin material on polyester base layer. Usually the crosslinking or curing is accomplished by the application of heat in conjunction with a free radical generating catalyst

A resin mixture of an isophthalic acid-fumaric acid-ethylene glycol polyester is preferred
and styrene used as a monomeric crosslinker

Many other additives can be incorporated into the polyester-based resin, e.g. B. the one before described, free radical generating catalyst. Examples of free radical generating catalysts include substances like

Lauroyl peroxide, senzoyl peroxide,

para-chloro-benzoyl peroxide,

2,4-dichlorobenzoyl peroxide,

Methyl ethyl ketone peroxide, Cyclohexanori'peroxid, Methyl isobutyl ketone peroxide, Dicumol peroxide,

2,2-bis- (4,4-di-tertiary-butylperoxy-cyclohexylpropane,

tertiary butyl peracetate,

tertiary butyl perbenzoic acid and

Azo-bis-isobutyronitrile.

Other additives can also be included, e.g. B. antioxidants, fillers, organic and inorganic dyes, lubricants, blowing agents, adhesives, fragrances, modifiers, solvents, Dispersants, wetting agents and other polymeric substances such as thermosetting resins, thermoplastic Resins and elastomers. All of these additives can be used in conjunction with the resin compounds according to the invention

fertilizers based on polyester are used, without sacrificing the advantages of the nitrogen-containing vinyl monomers according to the invention originate.

These polyester resin compositions are made by adding thermoplastic polymers such as polymethyl methacrylate. Polypropylene, polyethylene or high impact polystyrene, usually dissolved in a crosslinkable one Monomers such as styrene, adjusted so that they shrink little on curing ("low profile"). This ι ο Technique is explained in, for example, Australian Patent Specification 24 802/67

According to the process of the present invention, 5 to 30 parts by weight per 100 parts of polyester (A) on a nitrogen-containing vinyl monomer, namely on acrylamide, methacrylamide or dimethylaminoethyhnethacrylate Acrylamide added to the uncured resin sometime before the resin cures, Methacrylamide and dimethylaminoethyl methacrylate can be used together with the other additives mix slightly in the approach. They can be added to the batch at any stage. she must be mixed homogeneously into the batch before hardening. The resin set up in this way Polyester base can then be processed directly into a finished object or can be mixed with various natural or synthetic, fibrous materials in the form of loose fibers and / or threads (molding compounds par excellence) or with woven or non-woven panels made of fibrous material (panel molding compounds) mixed and then deformed to the desired shape and for crosslinking or hardening of the Materials are heated.

Preferably, 7 to 15 parts by weight per 100 parts of polyester (A) are used, since that of their Use deriving advantages, i.e. the increasing degree of adhesion of the coating materials, within of the latter area can be maximized. The amount of monomers is based on the polyester based; as some polyesters are in solution with styrene or another crosslinkable monomer on the Market, one should determine the amount of polyester in the solution and use this amount as Use the basis for the following calculations. The use of these novel monomers does not change the curing conditions conventional for these resins, nor the physical ones Property of the cured polymer as long as no more than about 30 parts are used; more Monomer leads to a deterioration in the physical properties of the cured resin.

Coatings of primer are then applied to the finished polyester moldings, which have been cured with low shrinkage or protective coatings or both applied for the purpose of adding to the finished material To give protection or to decorate the part, or a combination of these and others Reasons.

The coating materials which can be used on the molded polyester body cured with low shrinkage can be thermoplastic or heat-curable, resin-containing coatings of the solvent or emulsion type. The solvent-based coatings can be either an oil-based material or an alkyd-based material. Of the coating materials on the base oil are the most verbreiteren linseed oil and soybean oil by chemical reaction which is catalyzed by the oxygen in the air, on hard and durable coatings polymerize ^{'D' E} h ^'he be useful coatings on Alkydgrundlage by a reaction of Esterification-condensation type formed between a polybasic acid and a polyhydric alcohol and are used either all or in combination with modifying ingredients such as non-drying oils, semi-drying oils, drying oils, fatty oils, fatty acid oils and mixtures thereof
Examples of farinous acids include

Phthalic acid, isophthalic acid, Terephthalic acid, tetrachlorophthalic acid, Maleic acid, dodecyl maleic acid, Octadecenyl maleic acid, fumaric acid, Aconitic acid, itaconic acid, Trimellitic acid, tricarballylsic acid,

33'-thiodipropionic acid,

3-octenedione-lJ-acid,
Succinic acid, adipic acid,
1,4-cyclohexadiene-l ^ -dicarboxylic acid,
dhdidib

8,12-eicosadienedionic acid,

e-vinyl-10-octadecenedioic acid

and the corresponding

Acid anhydrides, acid chlorides and Acid esters, such as Phthalic anhydride, phthaloyl chloride and the

Dimethyl ester of phthalic acid.
Examples of polyhydric alcohols that can be used include

Glycerine, polyglycerine, pentaerythritol, Polypentaerythritol, mannitol, Trimethylolpropane, sorbitol, Methyltrimethylmethane, 1,4,6-octanetriol ButandioL PentandioL Hexandioi, Dodecanediol, octanediol Chloropentanediol grycerol monoallyl ether, Glycerine monoethyl ether, triethylene glycol,

2-Ethylhexandk> l-l, 4,

3,3'-thiodipropanoi

4,4'-sulfonyldihexanoL cyclohexanediol-1,4,

1,2,6-hexanetriol 1,3,5-hexanetriol,

Polyallyl alcohol,

13-bis (2-hydroxyethoxy) propane,

5,5'-dihydroxydiamyl ether,

Tetrahydrofuran-2 £ -dipropanoL Tetrahydrofuran-23-dipentanol,

2,5-dihydroxytetrahydrofuran,

Tetrahydrc thiophene-2 /> - dipropanol, Tetrahydropyrrole-24-propanoI,

4-hydroxy-33-ίlydΓoxytetrahydropyran,

23-dihydroxy-3,4-dihydro-1,2-pyran,

4,4'-sulfinyl dipropanol,

2,2-bis (4-hydroxyphenyl) propane,

2,2'-bis (4-hydroxyphenyl) methane

and the same.

For example for modifying oils that are mixed with the Afore-mentioned alkyd compounds can be combined, include linseed oil, rapeseed oil, cotton seed oil, Chinese wood oil, castor oil (including raw castor oil and dehydrated castor oil), soybean oil, Perilla oil, oiticica oil, linseed oil acids, coconut oil fatty acids, Ricinoleic acid, fatty acid glycerides, e.g. the glycerides of linoleic acid and linolenic acid, palmitic acid, oleic acid, stearic acid, fish oils, fish oleic acids, etc. The amount of the modifying oil can be in

Can be varied widely and can be from about 5 percent by weight to 70 percent by weight, preferably from about 10 percent to 15 percent by weight based on the total weight of the modifying agent Oils, polyhydric alcohols and polybasic acids (or anhydride, if this is used), which are present in the reaction mixture intended for the preparation of the alkyd resin are enough.

Covering fabrics based on emulsions, which are based on hardened, slightly shrinking polyester-based resin useful include a wide variety of types such as conventional styrene / butadiene (65/35) interpolymer latices, Styrene / butadiene latices that are mixed with the non-drying, semi-drying, drying, etc. oils are modified, the acrylic-based latices and the like. the These coating materials are produced by emulsion polymerization of the special monomer or monomer mixture and subsequent loading (by mixing) with the other components, such as oils, dyes and stabilizers.

In addition to the alkyd and emulsion-based coating materials described above, other coating materials can be used be used, e.g. B. lacquers, varnishes and other polymeric coatings. For examples of these include ethyl cellulose, nitrocellulose, cellulose acetate, cellulose acetobutyrate, vinylidene chloride, polyvinyl chloride, Styrene / acrylonitrile and others, such as acrylates, methacrylates, etc. Other coating materials, such as oil-modified Phenolic resins and oil-modified phenol-formaldehyde resins, urea-formaldehyde resins, melamine-formaldehyde resins and aniline-formaldehyde resins, are also useful and come with the present Invention certainly under consideration

The coating material can be applied in a variety of ways, e.g. B. by means of a paint brush, by spraying, dipping, roller coating, electrostatic Spraying, photolithography, rotogravure printing, Screen printing, etc. As the advantages that sidti by the addition of these nitrogen-containing vinyl monomers

Are coating material, is the process by which the Coating material is applied to the polyester resin surface, not particularly important as long as the correct coating and thickness are applied to the surface.

The following examples are intended to give the person skilled in the art an indication of how to put the invention into practice has to perform, and should also show him some of the advantageous aspects of the invention, namely the increased adhesion of the coating material to the finished surface of the resin with little shrinkage Polyester base. Unless otherwise stated, all parts are parts by weight per 100 parts of resin Polyester base, and all percentages are percentages by weight. The examples show that Results of an adhesion test. This test is carried out so that there are 10 parallel lines on the Surface of the coated polyester resin whose

ίο the distance from each other is 1387 mm. At an angle of about 60 "to these lines, another set of 10 parallel lines, spaced 1.587 mm apart, are scratched with the same knife in such a way that the original lines are crossed. A piece of masking tape is then put on the grooved surface pressed so that the adhesive part lies on the coated surface. The tape is pressed so that it can pass over onto the surface

then withdrawn. That the coating adhesion test has been passed is indicated by the fact that none Cover parts have been removed from the scratched surface area. Against it the failure in the adhesion test shows that pieces of the coating from the with scratches provided area remain on the adhesive of the masking tape. Such a test has in the Plastic technology has found widespread recognition and is generally used, especially in the automotive industry, applied

Example t

Low shrinkage polyester resin compositions were made according to those shown in Table Ia below

J5 Mixing instructions set up The ingredients were added to the viscous polyester-styrene resin in the order shown and mechanically mixed until a smooth paste was formed. The glass fibers were added last and the mixtures were pressed into smooth, 3.175 mm thick plates under a pressure of 133 bar for 4 minutes b ?! ! 35.0 ⁰ C NND g'hirtet then in an oven heated to 176.7 ° C for 10 minutes to complete the curing and drive off any volatile substances. The surface of each plate was then coated with a thermosetting epoxy alkyd coating material (828-2108 EI. DuPont de Nemours & Co, Ina) and cured for 30 minutes at 1623 ⁰ C The adhesion and other tests were performed on the finished plates The results are shown in Table Ib below

Table Ia Components

Sample A parts

Sample B
Parts

Sample C
Parts

Sample D
Parts

Sample E parts

Unsaturated polyester) 154 154 154 154 154 Shrinkage reducing additive-) 39 39 39 39 39 Acrylamide - 8th 15th - - Methacrylamide - - - 8th 15th Polymer! onsinhibitor ¹ ) 0.8 0.8 0.8 0.8 0.8 Thickener ⁴ ) 43 43 43 43 43 Catalyst ⁵ ) 8th 8th 8th 8th 8th

continuation

ίο

Components

Sample Λ parts of sample B
Parts

Sample C
Parts

Sample D parts

Sample E parts

Mold release agent ⁶ )
Sore reducing additive ⁷ )
Filler ¹ )
Glass fibers ")

23
394
123

23
394
123

8th 8th 8th 23 23 23 394 394 394 123 123 123

) Isophthalate fumarate polyester dissolved in styrene (65% polyester + 35% styrene) - Selectron "50204 - PPO Industries.

) 35% solution of high-impact polystyrene in monomeric styrene.

) Dibutyl-m-cresol - ΙοηοΓ 45 - Shell Chemical Co.

) Magnesium Oxide in Mineral Oil - Modifier M - W. R. Grace Co.

) (tert-butyl peroctoate - Lupersol * PDO - Lucidol Corp.

) Zinc tearate - Lubrazinc * - Witco Chemical Co.

¹ y Finely Parted Polyethylene - Microthene * F5I0 - USI Corp.

") Coated Caiciumcarbonai - Surf ** nini - Γ / ίηιιιυιιύ 31ι; ιιιμ <λΛ Cuii'i.

') 6.350 mm long glass razors - Owens Corning Fiberglas Co.

Table Ib

exams

Sample Λ sample B

Sample C

Sample D

Sample E.

Adhesion (9 spots on the plate)

passed the test
failed

Rockwell hardness "R"
Notched impact strength, J / m

0
9 5
4th 9
0 8th
1 9
0 110 110 110 110 HO 223.9 213.2 191.9 218.5 207.9

Example 2

Little shrinking polyester resin compositions were prepared according to the mixing instructions shown in Table Ha below order shown the viscous polyester-styrene resin added and mechanically mixed until a smooth paste was formed. The fiberglass were added last and the mixture pressed into smooth, 3.175 mm thick plates and under a Pressure of 133 bar for 4 minutes at 135.0 ° C and then Cured for 10 minutes at 176.7 ° C. The surface Each panel was then coated with a heat-hardenable epoxy-alkyd top coating material (828-2108 E I. duPont de Nemours & Co, Inc.) and covered for 30 minutes cured at 1623 ° C. Adhesion testing and other tests were performed on the finished panels The results are shown in Table Hb below

Components Table Ha Components

Sample sample sample D E F

Unsaturated polyester ¹ ) 154 154 154 Shrinkage reducing agent 39 39 39 Additive ² 1

Sample I)

Sample E.

Dimethylaminoethyl methacrylate

^4r> polymerization inhibitor ³ ) 0.8

Thickener ⁴ ) 3.9 Catalyst ⁵ ) 8 Mold release agent ⁶ ) 8

^w Shrinkage reducing additive 23 ⁷ )

Filler) 394

Glass fibers *) 123

0.8 3.9 8 8 23

394 123

Sample F.

l5

0.8 3.9 8 8 23

394 123

') Styrene disintegrator isophthalate fumarate polyester (65% polyester + 35% styrene) - Selectron "50204 - PPG Industries.

¹ ) 35% solution of high-impact polystyrene in monomeric styrene.

') Dibutyl-m-cresol - ionol "45 - Shell Chemical Co.

⁴ ) Magnesium Oxide in Mineral Oil - Modifier M - WR Grace Co.

⁵ ) tert-butyl peroctoate - LupcrsoP PDO -Lucidol Corp.

⁶ ) Zinc Stearate - Lubrazinc "- Witco Chemical Co.

⁷ ) Finely Parted Polyethylene - Micorthene * F510 - USI Corp.

") Coated Calcium Carbonate - Surfcx" MM - Diamond Shamrock Corp.
'') 6.350 mm long glass fibers - Owens Corning Fiberglass Co.

11th

Table lib

exams

Sample D

Sample E.

Sample F.

Adhesion (9 controls on the plate)

passed the P. 'exam 0 9

failed 9 0

Rockwell hardness »R« 110 106

Notched impact strength, J / m 362.4 373.1 309.1

These examples clearly demonstrate the increased adhesion of cover fabrics to surfaces hardened, low-shrinkage resin based on polyester, by incorporation of acrylamide, methacrylamide and dimethylaminoethyl methacrylate in the resin was obtained before the shepherd.

Comparative experiments

A polyester resin composition was prepared according to the compounding instructions shown in Table IIIa below The ingredients were added to the viscous polyester-styrene resin in the order shown and mixed by hand with a spatula until a smooth paste was formed. the

to glass fibers were finally added, and the mixture was pressed into a smooth, 3.175-mm thick plate and cured under a pressure of 3.45 bar for 4 minutes at 135.0 ⁰ C and then for 10 minutes at 176.7 ° C The Surface of each plate was then made with

a thermosetting epoxy-alkyd coating material (828-2108 E.I. duPont de Nemours & Co, Inc.) coated and cured for 30 minutes at 1623 ° C. The test adhesion and other tests were performed on the finished panels. The results will be shown below in Table 1Mb.

Table IHa Components

rehearse K L. M. N J 154 154 154 154 154 39 39 39 39 39 _ _ _ _ 15th

15th

15th

15th

Unsaturated polyester ¹ ) Shrinkage reducing additive ² ) Acrylonitrile Methacrylonitrile Methyl methacrylate Dimethylolacry lamid Vinyl acetate Polymerization inhibitor ¹ ) Thickener ⁴ ) Catalyst ⁵ ) ^{Mold release agent 6} )

Scnvrullulllil'iucn'iuCi 'additive ¹ )

Filler *) glass fibers ⁹ )

') Styrene-dissolved isophthalal fumarate polyester (65% polyester + 35% styrene) - Selectron' 50204 - PPG Industries.

² ) 35% solution of high impact polystyrene in monomcrem styrene.

³ ) Dibutyl-m-cresol - ΙοηοΓ 45 - lonol * 45 - Shell Chemical Co.

⁴ ) Magnesium Oxide in Mineral Oil Modifier M - V /. R. Grace Co.

⁵ ) tert-butyl peroctoate - Lupersol * PDO - Lucidol Corp. °) Zinc Stearate - Lubrazinc "- Witco Chemical Co.

⁷ ) Finely Parted Polyethylene - Microthene "F5I0 - USI Corp.

") Coated Calcium Carbonate - Surfex * MM - Diamond Shamrock Corp.

') 6.350 mm long glass fibers - Owens Corning Fiberglas Co.

- - - - 15th 0.8 0.8 0.8 0.8 0.8 4.3 4.3 4.3 4.3 4.3 8th 8th 8th 8th 8th 8th 8th 8th 8th 8th 23 23 23 23 11th 394 394 394 394 394 123 123 123 123 123

Table IHb

exams

Samples J

Adhesion (9 places on the plate) passed the test failed

Rockwell hardness "R" notched impact strength, J / m

2 1 0 0 2 7th 8th 9 9 7th Π0 112 108 110 109 213.2 223.9 191.9 202.5 202 ^

This example shows that other monomers - scgar some nitrogen-containing vinyl monomers - no increased adhesion of coating materials on the surface of hardened polyester resins.

Example 3

Example 1 was repeated with the modification that the hardened plates with a thermosetting Butadiene / styrene-latex coating material on a water base ι ο was painted and kept at 162.8 "C for 30 minutes have been hardened. The adhesion tests showed that the panels, no acrylamide or methacrylamide contained, failed in all cases, while those according to the present invention acrylamide and Panels containing methacrylamide passed the test in all cases. This example shows that the The advantages derived from the present invention are not based on the type of molded article on the hardened body the low-shrinkage polyester resin used cover fabric can be influenced.

Example 4

Example 1 was repeated with the modification that a thermoplastic lacquer coating material was applied to the hardened GRP surface was applied. the Adhesion tests showed that those plates, "2" e contained no acrylamide or methacrylamide failed in all cases, while those according to Teaching of the Present Invention Acrylamide and methacrylamide containing panels in all Cases passed the test. This example showed again, that the advantages deriving from the present invention, through the nature of the Low shrinkage hardened polyester molded cover material used are not influenced.

Claims (3)

Patent claims: 1. Thermosetting resin compositions made of an unsaturated polyester (A), a copolymerizable therewith, vinyl group-containing monomers (B), a free radical generating catalyst (C) and a thermoplastic polymer as a shrinkage-reducing additive (D) and optionally further conventional additives, characterized by a content of 5 to 30 parts by weight each 100 parts of component (A) of a nitrogen-containing vinyl monomer (E), namely of acrylamide, Methacrylamide or dimethylaminoethyl methacrylic IaL 2. Composition according to claim 1, characterized in that component (B) is styrene and the Component (D) is polystyrene and / or polyethylene 3. Use of the compositions according to claim 1 or 2 for the production of heat-hardened molded bodies with improved adhesion for cover fabrics.